We present an empirical analysis of TOM-Skype censorship and surveillance. TOM-Skype is an Internet telephony and chat program that is a joint venture between TOM Online (a mobile Internet company in China) and Skype Limited. TOM-Skype contains both voice-overIP functionality and a chat client. The censorship and surveillance that we studied for this paper is specific to the chat client and is ...

Censorship challenges to books in UK public libraries have received renewed attention recently, partly due to press coverage regarding libraries stocking ‘extremist’ material. Guidelines for dealing with these types of challenges and the general management of controversial material have been published; however there has been little recent research into the phenomenon of challenges to books in t...

We study cosmic censorship in the Reissner-Nordstrom charged black hole by means of quantum gravity holding near the apparent horizons. We consider a gedanken experiment whether or not a black hole with the electric charge Q less than the mass M (Q < M) could increase its charge to go beyond the extremal limit Q = M by absorbing the external charged matters. If the black hole charge could excee...

Censorship circumvention is often characterized as a cat-and-mouse game between a nation-state censor and the developers of censorship resistance systems. Decoy routing systems offer a solution to censorship resistance that has the potential to tilt this race in the favour of the censorship resistor by using real connections to unblocked, overt sites to deliver censored content to users. This i...

Motivated by recent interest in black holes whose asymptotic geometry approaches that of anti-de Sitter spacetime, we give a proof of topological censorship applicable to spacetimes with such asymptotic behavior. Employing a useful rephrasing of topological censorship as a property of homotopies of arbitrary loops, we then explore the consequences of topological censorship for horizon topology ...

To tackle the ubiquitous cybersecurity threats, a few countries have enacted legislation to criminalize the production, distribution and possession of computer misuse tools. Consequently, online hacker forums, which enable the provision and dissemination of malicious cyber-attack techniques among potential hackers or technology-savvy users, are subject to censorship. This project examines the m...

D the invaluable contribution of marketing folks (e.g., making markets work), they fail to enjoy the same freedom of speech as others. This fact is particularly egregious because unlike other groups that can use threats, force, or coercion, marketing folks rely only on speech. Although the U.S. Constitution never mentions commercial speech, the courts invented the concept to censor marketing fo...

Censorship resistance deals with an attempt to prevent censors from the acquaintance of distribution of a particular content through the network. Providing resistance against censoring is a very challenging and difficult task to achieve. However it is vital for the purpose of freedom of speech, mind and achievement of democratic principles in todays society. In this paper we define a model of a...

Over the past few years, the Internet has become a powerful means for the masses to interact, coordinate activities, and gather and disseminate information. As such, it is increasingly relevant for many governments worldwide to surveil and censor it, and many censorship programs have been put in place in the last years. Due to lack of publicly available information, as well as the inherent risk...

A core technique used by popular proxy-based circumvention systems like Tor, Psiphon, and Lantern is to secretly share the IP addresses of circumvention proxies with the censored clients for them to be able to use such systems. For instance, such secretly shared proxies are known as bridges in Tor. However, a key challenge to this mechanism is the insider attack problem: censoring agents can im...